20542551 has 8 divisors (see below), whose sum is σ = 27477744. Its totient is φ = 13651200.

The previous prime is 20542541. The next prime is 20542559. The reversal of 20542551 is 15524502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20542551 - 2¹¹ = 20540503 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20542559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9850 + ... + 11751.

It is an arithmetic number, because the mean of its divisors is an integer number (3434718).

Almost surely, 2^20542551 is an apocalyptic number.

20542551 is a deficient number, since it is larger than the sum of its proper divisors (6935193).

20542551 is a wasteful number, since it uses less digits than its factorization.

20542551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21921.

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 20542551 is about 4532.3891050968. The cubic root of 20542551 is about 273.8744118719.

The spelling of 20542551 in words is "twenty million, five hundred forty-two thousand, five hundred fifty-one".